Analog Devices Inc./Maxim Integrated MAX5089ATE+

Overview

MAX5089ATE+ from Maxim Integrated is a synchronous buck DC-DC converter IC with integrated 150mΩ high-side n-channel MOSFET, delivering up to 2A output current, adjustable output voltage down to 0.6V, and resistor-programmable switching frequency from 200kHz to 2.2MHz. It operates from 4.5V–5.5V or 5.5V–23V input and features a synchronous rectifier driver (DL), power-good (PGOOD) output, and thermal shutdown - used in automotive radio power supplies and IP phone point-of-load regulation.

For engineers reviewing the MAX5089ATE+ datasheet, MAX5089ATE+ pinout, MAX5089ATE+ application, or MAX5089ATE+ equivalent, key selection considerations include its synchronous topology for >90% efficiency at 3.3V/1.5A (12V_IN, 300kHz), integrated DL driver for external low-side FET control, PGOOD monitoring capability, and 16-pin TQFN (5mm × 5mm) thermal performance supporting 2.7W dissipation.

Technical Context

The MAX5089ATE+ implements voltage-mode PWM control with peak current limiting and digital soft-start (4096 oscillator cycles, 64 steps). Its adaptive break-before-make (BBM) circuit enforces 25ns dead time between high-side switch turn-off and DL-driven low-side FET turn-on to prevent shoot-through.

It integrates a 5.2V internal LDO (VL) for biasing control circuitry, with dropout operation below 5.5V input; VL is bypassed using 4.7µF to SGND and 0.1µF to PGND. The DL output sources 0.75A and sinks 1A to drive external synchronous rectifiers, while PGOOD asserts high only after V_OUT exceeds 92.5% of nominal and remains stable for ≥200ms.

Key Specifications

Pinout & Package

MAX5089ATE+ is housed in a thermally enhanced 16-pin TQFN package (5mm × 5mm, exposed pad), optimized for high-power density and low junction-to-case thermal resistance (1.7°C/W).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar synchronous buck converter applications.

Compared with MP2451DT-LF-Z and TPS54202DRCT, the MAX5089ATE+ uniquely combines 2A synchronous operation, PGOOD output, adaptive BBM timing, and 0.601V precision reference - making it optimal for automotive and telecom applications demanding both reliability and tight regulation.

Availability

MAX5089ATE+ is available at Aetrix Electronics and suitable for xDSL modem power supplies, automotive radio power supplies, and IP phone/WLAN access point point-of-load regulation requiring stable component supply, extended temperature support, and long-term industrial lifecycle assurance.

Supply support for MAX5089ATE+ includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Maxim Integrated (now part of Analog Devices) designs precision analog, mixed-signal, and power management ICs for demanding industrial, automotive, and communications applications.

The MAX5089ATE+ belongs to Maxim's high-frequency buck converter product line, engineered specifically for compact, high-efficiency point-of-load regulation in thermally constrained environments with rigorous power sequencing requirements.

FAQ

What is the maximum supported switching frequency for MAX5089ATE+?

The MAX5089ATE+ supports a maximum switching frequency of 2.2MHz, set by an external resistor on the OSC pin. At this frequency, minimum on-time is 120ns, enabling high-density designs with small inductors (e.g., 4.7µH). Operation at 2.2MHz requires careful PCB layout to manage gate drive losses and EMI, and the DL driver must be paired with a low-gate-charge external MOSFET to maintain efficiency. The MAX5089ATE+ maintains stable regulation and current limiting across the full 200kHz–2.2MHz range.

Does MAX5089ATE+ require an external low-side MOSFET?

Yes, the MAX5089ATE+ requires an external low-side n-channel MOSFET driven by its DL pin. Unlike fully integrated dual-MOSFET converters, the MAX5089ATE+ integrates only the high-side 150mΩ switch and provides a dedicated gate driver (DL) capable of 0.75A source / 1A sink current. This architecture allows designers to select optimal R_DS(on), Q_g, and thermal characteristics for their specific output voltage, current, and efficiency targets - a key advantage in automotive and telecom applications where thermal margin is critical.

How does the PGOOD function work on MAX5089ATE+?

The PGOOD output on MAX5089ATE+ is an open-drain, active-high signal that goes high-impedance only when three conditions are met: (1) V_OUT exceeds 92.5% of its nominal set point (e.g., >3.08V for 3.3V output), (2) the digital soft-start period has completed, and (3) the output remains stable for ≥200ms. It sinks up to 3mA and requires an external pullup resistor (typically to VL or 3.3V). PGOOD is forced low when EN is pulled low, enabling coordinated system shutdown. This behavior is confirmed in the Electrical Characteristics table (V_TH = 90–95% V_OUT, t_FD = 3µs).

Can MAX5089ATE+ operate from a 5V input supply?

Yes, the MAX5089ATE+ supports 4.5V–5.5V input operation by connecting V+ and VL together, placing the internal LDO in dropout mode where VL tracks V+. In this configuration, VL ≈ 5V, sufficient to bias all internal circuitry. The datasheet confirms operation down to 4.5V with full functionality, including PGOOD assertion, DL drive strength, and current limiting. For best stability, bypass V+ with ≥0.1µF ceramic and ensure EN is pulled to VL (not V+) to avoid logic threshold violations.

What thermal performance can be expected from MAX5089ATE+ in a standard 4-layer PCB?

In a standard 4-layer PCB with 2oz copper, 1in² thermal pad connected to internal ground planes, and the exposed pad (EP) soldered to SGND, the MAX5089ATE+ achieves ≤45°C junction-to-ambient rise at 2A/12V_IN/3.3V_OUT. Its 1.7°C/W junction-to-case thermal resistance and 2.7W rated dissipation enable full 2A operation up to +85°C ambient without derating. Thermal shutdown activates at +170°C with 25°C hysteresis, providing robust fault protection. Layout guidelines in the datasheet (Figures 5–6) emphasize minimizing thermal resistance from EP to PCB copper.